JP2016068188A - Deposit removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attachment removal method capable of efficiently removing a hard attachment, by reducing damage of a jig, in the attachment removal method for removing the attachment attached to the jig in a film forming process.SOLUTION: An injection material 1 having an abrasive material 11 on a surface of a core 10 having elasticity, is injected at a predetermined inclination angle α from the oblique direction into a surface 100a of a jig 100. When the injection material 1 collides with an attachment 110, the core 10 is elastically deformed, and the abrasive material 11 is displaced in the surface direction of the surface 100a of the jig 100 in response to deformation of the core 10. When the abrasive material 11 is displaced in the surface direction, the attachment 110 is rubbed in the surface direction by the abrasive material 11, so that the attachment 110 is removed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a deposit removal method for removing deposits attached to a jig used in a deposition apparatus in a deposition process.

  2. Description of the Related Art Conventionally, a film forming process is used for manufacturing semiconductor devices and jigs and tools having a hard film formed thereon. The material used for film deposition adheres to the jig used in these film deposition processes. Since these deposits may cause deterioration of product characteristics, it is necessary to remove them regularly. For example, a film forming apparatus used in a semiconductor device manufacturing process is provided with a tray on which a wafer as a processing material is placed, a susceptor that holds the processing material at a predetermined position on the tray, and a susceptor. A jig such as a counter plate is provided for controlling the gas flow inside. These jigs are formed of SiC or carbon whose surface is coated with SiC, the susceptor is formed of carbon, and the opposing plate is formed of quartz glass in consideration of usage conditions such as temperature and atmosphere.

  As a method for removing deposits attached to such a jig, Patent Document 1 discloses that a silicon carbide jig for a semiconductor manufacturing apparatus is immersed in a 10% by volume or more nitric-hydrochloric acid aqueous solution or hydrofluoric nitric acid aqueous solution for 30 minutes or more. Thus, a method for dissolving and removing deposits is disclosed. Moreover, as a method for removing the hard film, Patent Document 2 discloses that the hard film is removed by blasting by spraying abrasive grains harder than the hard film onto the surface to be processed on which the hard film such as TiN or TiCN is formed. A method is disclosed.

JP-A-8-78375 JP 2006-305694 A

When a hard deposit adheres to a jig made of a material that is easily damaged, for example, a hard coating such as GaN or Si ₃ N _{4 is formed} by a metal organic chemical vapor deposition method (MOCVD method) as a film forming process. In the case of adhering to the substrate, jigs such as a tray, a susceptor, and a counter plate are formed using quartz glass or carbon as a main material, and the hardness difference from the adhering material becomes large. That is, a hard deposit is present on the surface of the jig that is easily damaged.

  As in the technique described in Patent Document 1, the method of dissolving and removing deposits using a chemical solution requires several hours to remove such a hard film, resulting in poor work efficiency. Therefore, it is necessary to prepare a spare jig. Moreover, since a jig | tool is immersed in a chemical | medical solution, a big immersion tank and a lot of chemical | medical solutions are needed.

  Further, as described in Patent Document 2, when removing deposits with hard abrasive grains, jigs generally used in a film forming process, particularly jigs made of quartz glass and carbon, are hard. As soon as the adhering material was removed, it was exposed to a very strong working condition, and the surface of the jig was seriously damaged.

  Therefore, the present invention is a deposit removal method for removing deposits adhering to a jig in a film forming process, which can reduce damage to the jig and efficiently remove hard deposits. An object is to provide a kimono removal method.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a deposit removing method for removing deposits adhering to a jig in a film forming process, comprising hard particles from the surface of an elastic core. An injection material is prepared by projecting an abrasive material or by adhering an abrasive material made of hard particles to the surface of an elastic core, and the injection material is injected obliquely onto a jig surface, and the injection material The core is elastically deformed when it collides with the jig surface, and the adhering material is removed by displacing the abrasive in the surface direction on the jig surface.

  According to the first aspect of the present invention, the spraying material having the elastic core is sprayed on the jig surface from an oblique direction so that the spraying material is removed as in the conventional deposit removal method using the spraying material. Instead of removing the adhering substance by impact caused by the collision, the adhering substance can be removed by displacing the small abrasive material existing on the core surface in the surface direction along with the deformation of the core. The core is elastically deformed when the propellant collides with the jig, so the impact of the propellant on the jig can be reduced, and the small processing unit reduces the load on the jig with a force in the surface direction. Since deposits can be removed, damage to the jig can be reduced. Moreover, since the deposits can be removed from the jig simply by spraying the spray material onto the jig, the deposits can be removed easily and in a short time.

  According to a second aspect of the present invention, in the deposit removal method according to the first aspect, the technical means that the deposit is harder than the jig is used.

  As described in the second aspect of the present invention, when the deposit harder than the jig is removed, the jig is easily damaged, and therefore, the deposit removing method of the present invention can be suitably used.

  According to a third aspect of the present invention, in the deposit removal method according to the first or second aspect, a technical means is used in which the core of the injection material is made of rubber.

  When the core of the propellant is formed of natural rubber or various synthetic rubbers as in the invention described in claim 3, the impact force when colliding with the jig is obtained, and the hardness is set so as not to damage the jig. it can. Furthermore, since the elastic modulus can be sufficiently deformed when it collides with the jig, the displacement of the abrasive can be increased, so that the deposits can be efficiently removed.

  In invention of Claim 4, in the deposit | attachment removal method as described in any one of Claim 1 thru | or 3, the average particle diameter of the core of the said injection material is 0.1-2.0 mm. The technical means is used.

  If the core of the injection material is 0.1 to 2.0 mm as in the invention described in claim 4, the amount of deformation at the time of collision with the jig is large, and sufficient displacement in the surface direction of the abrasive is obtained. In addition, since the impact on the jig can be reduced, it can be suitably used.

  According to a fifth aspect of the present invention, in the deposit removal method according to any one of the first to fourth aspects, the abrasive material of the spray material is made of a material harder than the deposit, and has an average grain size. The technical means that the diameter is 0.9-22.0 μm is used.

  As in the fifth aspect of the invention, the abrasive material of the injection material is made of a material harder than the adhered material, whereby the hard adhered material can be efficiently removed. In addition, by making the average particle size of the abrasive material of the injection material 0.9-22.0 μm, it is possible to sufficiently remove the deposits, and the impact by the abrasive material when the injection material collides with the jig. It is possible to reduce the processing unit for the abrasive to remove the deposits, so that the damage to the jig can be further reduced.

  According to a sixth aspect of the present invention, in the deposit removal method according to any one of the first to fifth aspects, an injection angle α at which the spray material is sprayed onto the jig surface is relative to the jig surface. Therefore, the technical means that 40 ° ≦ α ≦ 80 ° is used.

  As in the invention described in claim 6, by setting the injection angle α to 40 ° ≦ α ≦ 80 ° with respect to the jig surface, the impact of the injection material can be reduced, and the jig is greatly damaged. This is preferable because it can be prevented from being applied, and the abrasive can be pressed against the deposit with an appropriate force to efficiently remove the deposit.

According to a seventh aspect of the present invention, in the deposit removal method according to any one of the first to sixth aspects, the jig is formed of quartz glass or carbon as a main material. Use means.

When the jig is made of quartz glass or carbon as a main material as in the invention described in claim 7, the jig is greatly damaged by the conventional deposit removal method using abrasive grains. The deposit removal method of the invention is preferable because it can keep very little damage.
Here, “made of quartz glass or carbon as a main material” means that other components are added or a film is formed (for example, carbon coated with SiC). It is a concept that includes

In the invention according to claim 8, in the deposit removal method according to any one of claims 1 to 7, the film forming process is a metal organic chemical vapor deposition method (MOCVD method).
The technical means is used.

When the metal organic chemical vapor deposition method (MOCVD method) is used as the film forming process as in the invention described in claim 8, the coating film to be formed is often hard such as GaN or Si ₃ N _4, and has a tray, a susceptor, and an opposing surface. Since there is a large difference in hardness from a jig such as a plate, the conventional method for removing an adhering material using abrasive grains results in significant damage to the jig if processing is performed under conditions that allow the adhering material to be removed. According to the deposit removing method according to the present invention, since the hard deposit can be efficiently removed without damaging the jig, the jig used in the metal organic chemical vapor deposition method (MOCVD method). It can be suitably used for removing deposits.

It is sectional explanatory drawing which shows the structure of an injection material typically. FIG. 1A is an overall view, and FIGS. 1B and 1C are enlarged views showing a fixed state of an abrasive. It is a schematic diagram of a structure of the blast processing apparatus used for removal of a deposit. It is a schematic diagram for demonstrating the mechanism of the deposit removal using the injection material which concerns on this invention.

  As shown in FIG. 1A, the injection material 1 used in the present invention is formed by adhering an abrasive 11 made of hard particles to the surface of a core 10 made of an elastic material. As shown in FIG. 1 (B), the abrasive 11 is disposed so as to protrude from the surface of the core 10, or as shown in FIG. Are fixed by a fixing agent 12 made of a resin material or the like. The injection material 1 as shown in FIG. 1B can be manufactured by, for example, a method of embedding the abrasive material 11 in the core 10 by a mechanical impact force. Further, the material, amount, and the like of the fixing agent 12 shown in FIG. 1C are selected so as not to hinder the displacement of the abrasive 11 accompanying the deformation of the core 10 described later. In both cases of FIGS. 1B and 1C, when the surface is in a non-wetting state, the injection materials 1 are prevented from being bonded to each other and the injection material 1 is prevented from adhering to the surface of the jig 100. Can do.

  The core 10 is made of a material that generates sufficient elastic deformation and recovers its shape when it collides with the jig 100 under injection conditions. In particular, when a rubber material such as natural rubber or various synthetic rubbers is used, an impact force when colliding with the jig can be obtained, and the hardness can be set so as not to damage the jig (for example, as defined in JIS K6253; 2012). Hardness is A30-90). Moreover, it can be set as the elasticity modulus (for example, 1-10 Mpa) which can fully deform | transform when it collides with a jig | tool. Further, since the liquid does not elute from the core 10 when it collides with the jig 100, the surface of the spray material 1 does not become wet. The core 10 is sufficiently larger than the abrasive 11 and, for example, one having an average particle size of about 0.1 to 2.0 mm can be used. In this embodiment, an irregular core having an average particle size of 0.7 mm is used. Various shapes such as a spherical shape and a chop can be adopted as the core.

  Further, for example, when the core 10 is made of an electrically insulating material such as ethylene propylene rubber, silicon rubber, nitrile rubber, urethane rubber, etc., since the injection material 1 is difficult to adhere to the jig 100 due to electrostatic force, preferable.

The abrasive 11 can be appropriately selected in consideration of the hardness of the deposit, etc. However, if a material made of a material harder than the deposit is used, the hard deposit can be efficiently removed. . For example, the deposits attached to the jig 100 such as a tray, a susceptor, and a counter plate used in the metal organic chemical vapor deposition method (MOCVD method) are often hard such as GaN and Si ₃ N ₄ which are film forming components. It is preferable to select a material harder than the deposit from hard materials such as aluminum oxide, silicon carbide, and diamond.

The abrasive 11 is made sufficiently smaller than the core 10 in order to reduce the impact of the spray material 1 and to reduce the damage to the jig 100 by reducing the processing unit in which one abrasive 11 removes deposits. It is preferable. For example, in this embodiment, silicon carbide having an average particle size of 0.9 to 22.0 μm is used.

  In addition, the abrasive 11 is preferably supported so as to cover 50 to 90% of the surface of the core 10 so as to cover the surface of the core 10 and sufficiently remove deposits.

  As shown in FIG. 2, the blast processing apparatus 2 used for removing the deposit is a nozzle 21 for spraying the spray material 1 onto the jig 100 and the spray material 1 is sprayed onto the jig 100 to remove the deposit. A blast chamber 22 for performing the cleaning, a table 23 for placing the jig 100 in the blast chamber 22, an injection material hopper 24 for storing the injection material 1 and supplying a predetermined amount of the injection material 1 to the nozzle 21, and a nozzle 21 Compressed air supply device 25 for supplying compressed air, and the cutting powder of the injection material 1 and the polished jig 100 are collected, and the reusable injection material and other dust particles (reuse) A classifier 26 for classifying the impregnated spray material and the cutting powder), and a dust collector 27 for exhausting and removing dust from the classifier 26.

  The nozzle 21 is configured to be able to inject the injection material 1 at a predetermined inclination angle α with respect to the surface of the jig 100.

  The deposits are removed by the following steps. First, the jig 100 for removing deposits is placed on the table 23 in the blast chamber 22, and the inclination angle α of the nozzle 21 is set to a predetermined inclination angle.

  Next, the injection material 1 is injected from the nozzle 21 under a predetermined injection condition, and is caused to collide with the jig 100 from an oblique direction. Compressed air is supplied to the nozzle 21 by a compressed air supply device 25, and the compressed air is jetted from the tip. The supply amount of the propellant 1 is controlled by the propellant hopper 24 and is supplied to the nozzle 21 by the negative pressure generated when the compressed air passes through the nozzle 21. The propellant 1 supplied to the nozzle 21 is mixed with compressed air to form a mixed air current, and is jetted onto the jig 100.

  At this time, the nozzle 21 is scanned with respect to the jig 100, or the jig 100 is fixed to a rotary table (not shown) arranged on the table 23 and the rotary table is rotated to rotate the jig 100. The jetting material 1 is made to collide with a desired range by rotating it or the like, and the deposits are removed.

  The spray material 1 scattered after colliding with the jig 100 and the deposits removed from the jig 100 are sucked and collected by the fan of the dust collector 27 and are pneumatically transported to the classification device 26 for classification. Of the spray material 1 classified in the classifier 26, only the reusable spray material 1 is re-introduced into the storage tank of the spray material hopper 24 and used.

FIG. 3 schematically shows a method for removing deposits by the spray material 1. Here, attention is paid to the behavior of the abrasives 11a and 11b shown in black. Here, the case where the deposit 110 such as a GaN film is adhered to the surface 100a of the jig 100 such as a counter plate made of quartz glass will be described as an example.

As shown in FIG. 3B, when the spray material 1 injected in an oblique direction with an inclination angle α from the nozzle 21 collides with the jig 100 as shown in FIG. The core 10 is elastically deformed along the surface 100a (attachment 110).

At this time, the abrasive 11a is displaced leftward in the figure as the core 10 is deformed. Since the abrasive 11 is displaced while the pressing force against the jig 100 is loaded while the spray material 1 is in contact with the deposit 110, the surface of the deposit 110 is subjected to the pressing force. By rubbing in the surface direction.

Subsequently, the core 10 is further deformed, and as shown in FIG. 3C, the abrasive 11a is further displaced leftward and the abrasive 11b is displaced rightward. As the abrasive material 11 that contacts the surface of the deposit 110 is displaced in this way, the deposit 110 is rubbed in the surface direction by the abrasive material 11, and a part of the deposit 110 is removed. At this time, the adjacent abrasive 11 may be displaced so as to be separated.

Then, as shown in FIG. 3D, the propellant 1 recovers its shape due to the elasticity of the core 10 and rebounds from the jig 100, and the removed deposit 110 is scattered together.

  As described above, by injecting the injection material 1 having the elastic core 10 onto the surface 100a of the jig 100 from an oblique direction, as in the conventional method for removing the deposit using the injection material, Rather than removing the deposit by impact due to a collision, the deposit 110 is removed by the small abrasive 11 existing on the surface of the core 10 being displaced in the surface direction of the jig 100 as the core 10 is deformed. it can. Since the core 10 is elastically deformed when the propellant 1 collides with the jig 100, the impact of the propellant 1 on the jig 100 can be reduced. In addition, the deposit 110 can be removed with a small processing unit with a force in a surface direction with a small load on the jig 100. Thereby, damage to the jig 100 can be reduced. Moreover, since the deposit 110 can be removed from the jig 100 simply by spraying the spray material 1 onto the jig 100, the deposit 110 can be removed easily and in a short time. Here, since the abrasive 11 is displaced in the surface direction along with the deformation of the core 10 and it is necessary to sufficiently apply a force in the surface direction to the deposit 110, the abrasive material 11 adheres to the core 10 with an adhesive, for example. It needs to be firmly fixed, not being done. Furthermore, since the shape of the injection material 1 that collided with the jig 100 returns to its original shape when it bounces back, it can be used repeatedly.

  If the core 10 of the injection material 1 is formed of a rubber material, the elastic modulus of the core 10 is low (about several MPa), and deformation when colliding with the jig 100 can be increased, so that impact can be reduced. Moreover, since the displacement of the abrasive 11 can be increased, the deposit 110 can be efficiently removed.

  When the average particle size of the core 10 of the injection material 1 is 0.1 to 2.0 mm, preferably 0.3 to 1.5 mm, the amount of deformation at the time of collision with the jig 100 is large, and the surface direction of the abrasive 11 Can be sufficiently used, and the impact on the jig 100 can be reduced.

By making the abrasive 11 of the spray material 1 a material harder than the deposit 110, the hard deposit 110 can be efficiently removed. Further, by setting the average particle size of the abrasive 11 to 0.9 to 22.0 μm, preferably 0.9 to 10.0 μm, it is possible to sufficiently remove the deposits, and the injection material 1 is used as the jig 100. Since the impact caused by the abrasive 11 when it collides with the workpiece can be reduced and the processing unit can be reduced, damage to the jig 100 can be further reduced. This is particularly effective when the deposit 110 has a large hardness difference from the jig 100, for example, when the deposit 110 is hard such as GaN or Si ₃ N ₄ . Depending on the strength of the deposit 110 and the strength of the jig 100, the average particle diameter of the abrasive 11 can be set to about 0.1 μm. In addition, the above-mentioned average particle diameter can be measured by the electrical resistance test method prescribed | regulated to JISR6002; 1998.

  By setting the injection angle α to 40 ° ≦ α ≦ 80 °, preferably 45 ° ≦ α ≦ 65 °, with respect to the surface 100a of the jig 100, the impact of the injection material 1 can be reduced. This is preferable because the abrasive 11 can be pressed against the deposit with an appropriate force and the deposit 110 can be efficiently removed.

Furthermore, if the inclination angle α is reduced, the area where the spray material 1 collides with the surface 100a of the jig 100 can be increased, so that it is possible to remove the deposit 110 in a wide area at a time, which is efficient.

The removal method of the deposit | attachment of this invention can be used suitably when a hard deposit | attachment adheres to the jig | tool consisting of a material which is easy to damage. For example, a metal organic chemical vapor deposition method (MOCVD method) can be given as such a film forming process. When a metal organic chemical vapor deposition method (MOCVD method) is used as a film forming process, a coating film to be formed is often hard such as GaN or Si ₃ N ₄ . Jigs such as trays, susceptors, and counter plates are formed using quartz glass or carbon as a main material, and have a large difference in hardness from the deposits. Here, “made of quartz glass or carbon as a main material” means that other components are added or a film is formed (for example, carbon coated with SiC). It is a concept that includes In the deposit removal method using the conventional abrasive grains, the jig is greatly damaged when the treatment is performed under the condition that the deposit can be removed. However, according to the deposit removal method according to the present invention, Since it is possible to efficiently remove hard deposits without damaging them, it can be suitably used for removing deposits on jigs used in metal organic chemical vapor deposition (MOCVD).

(Example of change)
The deposits can be removed using a plurality of nozzles. In this case, it arrange | positions so that the injection material which each nozzle injects may not mutually interfere. Thereby, processing efficiency can be improved.

In the above-described embodiment, the blast processing apparatus including the suction type nozzle is used. However, after the amount of the injection material in the storage tank is determined by the compressed air supplied to the storage tank of the injection material hopper, the injection material is injected. The present invention can also be applied to a blasting apparatus provided with a pressure type nozzle.

(Effect of embodiment)
According to the deposit removal method of the present invention, damage to the jig 100 can be reduced, and the deposit 110 can be removed from the jig 100 simply by spraying the spray material 1 onto the jig 100. The deposit 110 can be removed easily and in a short time. Moreover, the said effect can be show | played more effectively by making the structure of the core 10, the abrasive material 11, the injection angle (alpha), etc. appropriate.

  Examples of the present invention are shown below together with comparative examples. Here, the present invention is not limited to the following examples.

  In order to simulate a counter plate made of quartz glass whose hard deposit is GaN, a sample obtained by forming a GaN film of about 50 μm on a quartz glass substrate was prepared.

  In the embodiment, the propellant is 90% of the surface area of the core made of silicon carbide having an average particle diameter of 12 μm on the core of a rubber material which is an irregular elastic body having an average particle diameter of 0.7 mm. The one fixed to the surface was used. As the core, natural rubber was used in Example 1, and ethylene propylene rubber was used in Example 2. In the comparative example, comparative example 1: alumina abrasive grains having an average particle diameter of 14.0 μm, Vickers hardness Hv2200 (WA # 800: manufactured by Shinto Kogyo Co., Ltd.), comparative example 2: average particle diameter of 180 μm, Mohs hardness M3.5 Melamine resin abrasive grains (PSM80: manufactured by Shinto Kogyo Co., Ltd.), Comparative Example 3: Glass powder (GP105: manufactured by Shinto Kogyo Co., Ltd.) having an average particle size of 180 μm and Vickers hardness Hv530 were used.

  As an apparatus for injecting a spray material onto a sample, a blast processing apparatus MY-30 manufactured by Shinto Kogyo Co., Ltd. was used. As the nozzle, a suction type (gravity type) nozzle having a nozzle diameter of φ8 mm was used. The processing conditions were a nozzle tilt angle of 60 °, an injection time of 510 seconds, and an injection distance of 100 mm. The injection pressure was 0.4 MPa in the example and comparative example 2, 0.25 MPa in comparative example 1, and 0.07 MPa in comparative example 3.

The evaluation of the deposit removal treatment was performed from the two viewpoints of whether the removal of the coating film, which was a deposit, was successful, and whether the damage to the substrate was within an acceptable range. The damage to the substrate was evaluated based on the level difference between the treated part and the untreated part, and a threshold value of 50 μm was used.

The evaluation results are shown in Table 1. In Examples 1 and 2, it was possible to remove the film satisfactorily in a short time, and damage to the substrate was within an allowable range. On the other hand, in Comparative Example 2, the film could not be removed satisfactorily, and in Comparative Examples 1 and 3, the film could be removed, but the substrate was severely damaged.

  According to the example, the deposits can be removed in a state where the damage to the substrate is extremely small in a short time, and the effect of the present invention was confirmed.

  Further, when the sample for which the operation of removing the film was completed was observed after air-blow cleaning, the amount of the propellant adhering to the sample was smaller in Example 2 in which an electrically insulating material was used for the core.

DESCRIPTION OF SYMBOLS 1 ... Injection material 2 ... Blast processing apparatus 10 ... Core 11 ... Abrasive material 12 ... Adhesive agent 21 ... Nozzle 22 ... Blasting chamber 23 ... Table 24 ... Injection material hopper 25 ... Compressed air supply device 26 ... Classification device 27 ... Dust collector 100 ... Jig 100a ... surface 110 ... deposit

Claims (8)

A deposit removal method for removing deposits adhering to a jig in a film forming process,
Prepare an injection material in which an abrasive material made of hard particles is projected on the surface of an elastic core, or an abrasive material made of hard particles fixed on the surface of an elastic core,
The jetting material is jetted on the jig surface from an oblique direction,
The deposit removal method, wherein the core is elastically deformed when the spray material collides with the jig surface, and the deposit is removed by displacing the abrasive in the surface direction on the jig surface. The said deposit | attachment is harder than the said jig | tool, The deposit | attachment removal method of Claim 1 characterized by the above-mentioned. The deposit removal method according to claim 1 or 2, wherein the core of the spray material is made of rubber. The deposit removal method according to any one of claims 1 to 3, wherein the core of the spray material has an average particle diameter of 0.1 to 2.0 mm. The hard particles of the spray material are made of a material harder than the deposit, and have an average particle size of 0.9 to 22.0 μm. How to remove deposits. The injection angle α at which the spray material is sprayed onto the jig surface is 40 ° ≦ α ≦ 80 ° with respect to the jig surface. Deposit removal method. 7. The deposit removing method according to claim 1, wherein the jig is made of quartz glass or carbon as a main material. 8. The deposit removing method according to claim 1, wherein the film forming process is a metal organic chemical vapor deposition method (MOCVD method).

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